So, I'm a new Beseler 45MXT owner. I've wanted one for years, and finally got one. Once I got it set up, I noticed right away that something is vignetting the corners of the projected image. (See photo) I'm enlarging 4x5 negatives with a 135mm Nikon enlarging lens. My light source is the Dichro 45S color head, with the 4x5 mixing chamber. The upper bellows are as compressed as possible. As best I can determine, it's something with the placement of the negative in relation to the light source. So, I figure I could do one of two things: 1. Try a 150mm enlarging lens. The 135mm I have now is closer to the negative and is 'looking' into the corners and picking up the edges of the light source, or so I think ... A 150, being slightly farther from the negative, might not have as wide of an angle of view. 2. Swap out the Dichro 45S for a Aristo D2 cold light. The cold light may seat down further and get closer to the negative than the 45S, but I have no way of knowing for sure. Anyone else seen anything like this before? I'd greatly appreciate any help or advice.